1. Field of the Invention
This invention relates to writing stylus for "touch screen" devices. "Touch screen" devices are devices that can sense and record when an object contacts their surface. The invention relates to such devices that sense and record or relay data when contacted by passive-non-electrical objects. Particularly, the invention is directed to a writing stylus for touch screen devices that the user can wear on or attach to their finger.
2. Related Art
Recently personal digital assistants ("PDA's") such as the Palm Pilot from 3COM, Microsoft Windows CE based handheld PC's, the Apple Newton, or personal organizers such as the Sharp Zaurus have been produced with touch sensitive screens. These computing devices typically include a simple wooden or plastic pen-type stylus with a non-marking tip. The stylus is touched to the screen in order to act like a mouse (to move the cursor, highlight text, etc.) or to enter information (characters for handwriting recognition, drawings, etc.). A non-marking implement is used so that the screen of the device will not be scratched or damaged when touched. In addition, these pen-style styli must usually be over four inches (10 cm.) long to be properly supported by a user's hand. This requires a significant amount of space, within the case of a touch screen device, for storage of the stylus.
Moreover, the stylus for such devices is often lost. Copies of the original stylus may or may not be available. Therefore replacement styli are necessary. In addition, existing styli are pen-shaped. This requires the user to stop what they are doing and pick up or put down these specialized styli when they wish to enter information in the touch screen device while doing other work such as typing or writing. In place of the normal stylus a user will occasionally use a fingertip as a stylus; unfortunately a fingertip is blunt and a user often cannot position their finger with sufficient accuracy to locate the cursor or enter other data where needed on the screen.
Recently two patents have been issued regarding digital styli to the A. T. Cross Company. These U.S. Pat. Nos. 5,635,682 and 5,627,348 cover the creation of a replaceable non-marking stylus core in conventional pen-shaped writing instruments, and the composition of the non-marking stylus tip that will produce a "sound and feel" comparable to traditional writing on paper. Neither of these inventions contemplate the use of a non-marking stylus attached to or covering a portion of a user's finger.
Other prior art contemplates the use of a writing implement, i.e., a pencil or pen, attached to a finger. For example, U.S. Pat. No. 198,484 of 1877 uses a perforated finger sleeve to attach a pen, "a pencil or other writing or marking instrument" to one's finger. Other patents, including U.S. Pat. No. 361,535 of 1887, and U.S. Pat. No. 5,405,206, use an assortment of rings, metal clamps or thimble type devices to attach writing instruments (most of which use ink or some other physical marking process) to one's finger. U.S. Pat. No. 4,738,556 uses a Velcro strap to secure a pen in-line with the end of a finger. A recent fingertip stylus device has been shown on the Internet. The device is a rotatable bent wire ring including a tip extension for contacting a touch screen. Still other prior art contemplates the use of finger mounted writing implements for digital tablets, however, these patents contemplate use of devices which gather or send electrical signals from the device tips and do not contemplate a passive, non-marking tip. These patents include U.S. Pat. No. 4,954,817 and U.S. Pat. No. 5,706,026.